1. Field of the Invention
The present invention relates to method and apparatus for transporting an article, ad more particularly to method and article for transporting an article by utilizing periodic deformation of a plurality of bar-like members.
2. Description of the Prior Art
In prior art article transport apparatus, a motor or a linear motor which utilizes an electromagnetic force has been widely used as a drive source for transport. However, since such an actuator is constructed by cores, copper windings and permanent magnets, the number of components is large and they impose a heavy weight. Accordingly, it is difficult to attain a compact and light transport apparatus.
On the other hand, a motor or linear motor in which a travelling vibration wave comprising a lateral wave and a longitudinal wave is generated on a surface of an elastic member by an ultrasonic wave resonator and the vibration wave is converted to rotational or unilateral motion has been proposed (Japanese Patent Application Laid open No. 148682/1983). However, since such an actuator uses a travelling vibration wave, it is necessary to continuously circulate the vibration wave and it is essential to provide an area in which the vibration wave circulates. As a result, when the transparent apparatus is constructed by using such a motor, it is difficult to attain a transport apparatus which is sufficiently small and light to meet these requirements.